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Solid-phase Synthesis of [4.4] Spirocyclic Oximes
Published on: February 6, 2019
Taming the reactive intermediates: the nazarov cyclization as a programmable platform
Yunfei Cheng1, Ye Yuan2, Qun Sun2
1School of Chemistry and Chemical Engineering, Huangshan University, Huangshan, 245061, China. 600127@hsu.edu.cn.
Summary
The Nazarov cyclization is now a versatile synthetic tool, moving beyond acid catalysis. Modern methods offer better control over initiation, structure formation, and stereochemistry, as shown in natural product synthesis.
Area of Science:
- Organic Chemistry
- Synthetic Chemistry
- Reaction Mechanisms
Background:
- The Nazarov cyclization traditionally relies on acid catalysis for electrocyclization.
- This method has limitations in scope and substrate compatibility.
- There is a need for more controlled and versatile synthetic strategies.
Purpose of the Study:
- To review the evolution of the Nazarov cyclization.
- To highlight modern strategies for controlling the reaction.
- To showcase its application in complex molecule synthesis.
Main Methods:
- Summarizing advancements in Nazarov cyclization initiation.
- Describing methods for controlling oxyallyl cation trapping.
- Reviewing stereochemical control strategies, including catalysis.
Main Results:
- Modern initiation techniques (e.g., photochemistry, catalysis) offer alternatives to harsh acids.
- Diverting the intermediate oxyallyl cation enables diverse intra- and intermolecular reactions.
- Stereochemical outcomes can be precisely controlled using various chiral systems.
Conclusions:
- The Nazarov cyclization has transformed into a flexible synthetic platform.
- Advanced control points allow for the synthesis of complex molecular architectures.
- These developments are crucial for natural product synthesis and drug discovery.
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